D&B
Unique nine-digit D&B D-U-N-S Number is assigned to each business. It is used as "a tool for identifying, organizing and consolidating information about businesses. Companies worldwide use it to link information about suppliers, customers and trading partners, providing them a more complete picture of risks and opportunities in their business relationships." (www.dnb.com).

GSA
GSA stands for General Services Administration, the landlord and general store for much of the federal government. A GSA Schedule (contract) is a formal agreement between a company and a federal government. Government agencies need the schedule number in order to place orders under the GSA schedule.